How should strawberries be treated for spider mites after fruiting? - briefly
Apply a targeted miticide—such as sulfur, neem oil, or a licensed acaricide—directly to foliage and stems right after harvest, avoiding contact with the fruit. Then remove damaged leaves, thin the canopy, and keep humidity low to suppress any remaining mite populations.
How should strawberries be treated for spider mites after fruiting? - in detail
After the berries have been harvested, spider‑mite control must shift from protecting fruit to preserving foliage and preparing the plants for the next season. The primary objectives are to reduce mite populations, prevent rebound, and promote plant vigor.
First, remove all fallen fruit, leaves, and debris that can harbor mites and their eggs. Dispose of the material away from the garden or compost it in a hot bin. Then, prune heavily infested stems, cutting back to healthy tissue. Sterilize pruning tools with a 10 % bleach solution to avoid spreading the pest.
Next, apply a series of non‑chemical and chemical measures:
- Water spray: A strong jet of water applied to the undersides of leaves dislodges mites and eggs. Repeat every 5–7 days for two weeks, especially after rain when humidity is high.
- Miticidal soaps: Use a horticultural oil or insecticidal soap at the label‑recommended rate. Cover both leaf surfaces and repeat after 7 days, then again after 14 days if mite counts remain above threshold.
- Biological agents: Release predatory mites such as Phytoseiulus persimilis or Neoseiulus californicus. Introduce them when mite numbers are moderate; a release rate of 50–100 predators per square meter is effective.
- Systemic acaricides: If the infestation is severe, apply a systemic product containing abamectin or spirodiclofen according to label instructions. Rotate with a different mode of action to delay resistance.
- Cultural practices: Maintain adequate irrigation to keep leaf surfaces moist, reduce plant stress, and encourage rapid growth. Mulch with straw or pine needles to keep soil temperature stable and minimize dust that favors mite dispersal.
Finally, monitor weekly with a hand lens or sticky traps. When counts drop below 2 mites per leaf, cease applications but continue preventive sprays every 3–4 weeks throughout the growing season. Store or destroy any remaining plant material at season’s end to break the mite life cycle before winter.